Circuit closing and breaking device.



No. 786,589. PATENTED APR. 4, 1905.

w. J. MURDOOK. CIRCUIT CLOSING AND BREAKING DEVICE.

APPLICATION FILED JULY 21, 1904.

UNiTeio STATES Patented April 4;, 1905.

PATENT Orricn.

ClRCUIT CLOSiNGi AND BREAKING DEVlCE.

SPECIFICATION forming part of Letters Patent No. 786,589, dated April 4,1905.

Application filed July 21, 1904. Serial No- 217,567.

To all whom, it may concern:

Be it known that 1, WILLIAM J. MURDooK, of Boston, in the county ofSufiolk and State of Massachusetts, have invented certain new and usefulimprovements in Circuit Closing and Breaking Devices, of which thefollowing is a specification.

This invention relates to a device for closing and breaking an electriccircuit, the device being of the character known as a pushbutton andcomprising a casing or holder of insulating material and two metalliccontact-pieces attached thereto and insulated from each other thereby,said pieces being connected with the circuit-wires and normallyseparated from each other to break the circuit.

The invention has for its object to provide an improved device of thischaracter of such construction as to materially reduce the expense ofconstruction and the liability of dis,- placement of the contact-piecesor either of them.

The invention consists in the improvements which 1 will now proceed todescribe and claim.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a plan view showing the base and the contact-piecesof a circuit closing and breaking device embodying my invention, the topportion of the casing and the push-knob being removed. Figs. 2 and 3represent the contact-pieces separated from the holdingbase. Fig. atrepresents a view similar to Fig. 1, showing a part of the outercontact-piece broken away. Fig. 5 represents a section on line 5 5 ofFig. 1, showing in dotted linesthe cap portion of the casing and thepush-knob therein. Fig. 6 represents a section on line 6 6 of Fig. 1.

The same reference characters indicate the same parts in all thefigures.

In the drawings, a and 6 represent the contact-pieces of a circuitclosing and breaking device or push-button, the same being of anysuitable metal or material which is a conductor of electricity.

represents the base or holder to which the contact-pieces are affixed,said base forming a part of a casing which is completed by theconnection with the base of a cap (Z. (Shown by dotted lines in Fig. 5.)The base is provided with an externally threaded shoulder 21, whichengages an internal thread formed in the cap (Z.

6 represents the usual push knob or button, which is movable in anaperture in the cap a and bears against the outer portion of the springcontact-piece Z), the resilience of said piece normally holding the knobor button (Z against the cap, as indicated in Fig. 5. When the button 0is pushed inwardly, it forces the spring-piece Z) into contact with theanvil-piece a, thus closing the circuit.

In carrying out my invention I form the base 0 of a suitable plasticmaterial or composition which is adapted to be molded and to becomerigid, the said material or composition being a non-conductor ofelectricity. The contact-pieces a and b are provided, respectively, withshanks a and b, which are seated within the body of the base 0, thisbeing accomplished by locating the shanks a and below the plane of theouter or upper surface of the base 0 and extending portions 0 c of thema terial of said base over the outer surfaces of said shanks. Thecontact-pieces are seated on or embedded in the base while the materialof the latter is in plastic condition, and the portions of the base thatare extended over the shanks of the contact-pieces when hardenedsecurely confine the contact-pieces in place. The shanks of thecontact-pieces are preferably offset, as shown in the drawings, so thateach shank is located below the plane of the outer surface of the base,while the outer portion of the contact-piece a is arranged substantiallyflush with said outer surface, as shown in Figs. 5 and 6, the outerportion of the spring contact-piece b overhanging the outer surface ofthe base and the outer portion of the contact-piece a.

The shanks of the contact-pieces are provided with orifices 3 4c, theorifices 3 receiving the binding-screws 5, which secure the circuitwiresto the contact-pieces, while the orifices 4 receive screws which attachthe base to its support. Orifices coinciding with the orifices 4 aremolded in the base 0, and internallythreaded metallic bushings arepreferably embedded in the base to coincide with the orilices lush-button com )rising a base of insulating 3 and engage the screws 5.

6 represents an orilice formed in the base between the screws 5 for thepassage of the circuit-wires through the base.

I claim-- 1. A circuit closing and breaking device or push-buttoncomprising a base of insulating material, and metallic contact-mecca;each having a shank embedded in and covered by the base, and an exposedportion located above the base, one of said exposed portions beingresilient and normally separated from the other although adapted to bemoved into contact therewith, the said base having integralshank-confining portions extendimg' over and confining the said shanks.

2. A circuit closing and breaking device or material, and metalliccontact-pieces each having an ex posed portion and a shank otlset fromthe exposed portion and embedded in the base below the outer surface ofthe latter, one of said exposed portions being resilient and normallyseparated from the other although adapted to be moved into contacttherewith, the said base having integral shank-conlining portionsextending over and confining the shanks and forming parts of the outerface of the base.

In testimony whereof I have afiixed my signature in presence of twowitnesses.

WILLIAM J. MURDOCK. lrVitnosses:

G. F. BROWN, E. BATOHELDER.

